The Nagaras were
completed in 1922-25 and resembled
the earlier Kumas
except for their 24” (61 cm) torpedo armament. Though these
were not originally capable of firing the deadly Long Lance,
which required special equipment to handle their pure oxygen supply,
the class was in the process of having its torpedo tubes updated
at the outbreak of war. The conning tower was left unarmored to
make room for aircraft handling facilities.

In late 1944, Isuzu
was converted to an antiaircraft cruiser intended to serve as the
flagship of an antisubmarine
group.